UV inkjet printing of vision control panels

Abstract

This invention concerns vision control panels and a method of UV inkjet printing vision control panels. A substantially imperforate light permeable material is partially printed with a ‘print pattern’ comprising a base layer and a design layer comprising a design colour layer. The method is limited to digital UV inkjet printing of all the superimposed layers required to make such panels. Optionally, the method uses a novel printhead array with a novel order of ink color supply and/or novel software to enable the required build-up of ink layers, for example of black, optional silver, white, cyan, magenta, yellow and process black colors. Printing is preferably arranged so that the base layer and design color layer are printed in the minimum number of passes of the printhead assembly of the digital UV inkjet printer to achieve the desired effect, preferably in one pass of the printhead assembly.

The invention claimed is: 
     
       1. A method of making a panel comprising an imperforate sheet of colored or colorless light permeable material partially printed with a print pattern comprising a plurality of ink layers, said ink layers comprising a base layer, said ink layers comprising a design layer, said design layer comprising a design color layer, said print pattern comprising a plurality of connected and/or unconnected print pattern elements, said print pattern subdividing the panel into a plurality of areas of said print pattern and/or a plurality of unprinted areas of said light permeable material, and wherein the percentage of unprinted light permeable material is at least 5% and the light transmissivity of the panel is at least 10%, wherein a cross-section can be taken through said panel comprising two outer edges of said sheet of light permeable material and alternate printed portions and unprinted portions and a plurality of said printed portions comprising a part of said base layer and a plurality of said plurality of said printed portions comprising a part of said design layer, characterized in that all of said plurality of ink layers comprise UV cured ink comprising an agglomeration of overlapping and/or contiguous and/or spaced individual deposits of UV cured ink, said method comprising:
 (i)providing a substantially imperforate sheet of colored or colorless light permeable material, and   (ii) printing both said base layer and said design layer by a digital inkjet printer, wherein all said plurality of ink layers comprise UV cured ink printed by said digital inkjet printer, and wherein all said plurality of ink layers are applied within said printed portions and are not applied within said unprinted portions, wherein said printing is undertaken in a printing sequence, and wherein at one point in time during said printing sequence there are at least two more of said plurality of ink layers printed within one of said printed portions than the number of said plurality of ink layers printed within another of said printed portions.   
     
     
       2. A method as claimed in  claim 1  of making a panel comprising an imperforate sheet of colored or colorless light permeable material partially printed with a print pattern comprising a plurality of ink layers, said ink layers comprising a base layer, said ink layers comprising a design layer, said design layer comprising a design color layer, said print pattern comprising a plurality of connected and/or unconnected print pattern elements, said print pattern subdividing the panel into a plurality of areas of said print pattern and/or a plurality of unprinted areas of said light permeable material, and wherein the percentage of unprinted light permeable material is at least 5% and the light transmissivity of the panel is at least 10%, wherein a cross-section can be taken through said panel comprising two outer edges of said sheet of light permeable material and alternate printed portions and unprinted portions and a plurality of said printed portions comprising a part of said base layer and a plurality of said plurality of said printed portions comprising a part of said design layer, said method comprising:
 (i) providing a substantially imperforate sheet of colored or colorless light permeable material, and 
 (ii) printing both said base layer and said design layer by a digital inkjet printer, wherein all said plurality of ink layers are applied within said printed portions and are not applied within said unprinted portions, wherein said printing is undertaken in a printing sequence, and wherein at one point in time during said printing sequence there are at least two more of said plurality of ink layers printed within one of said printed portions than the number of said plurality of ink layers printed within another of said printed portions, wherein said printing comprises printing all of said plurality of ink layers over a first part of the overall area of said print pattern before any of said plurality of ink layers are printed over a second part of the overall area of said print pattern. 
 
     
     
       3. A method as claimed in  claim 2 , wherein:
 said digital inkjet printer comprises a plurality of printheads in a printhead assembly on a printhead beam, wherein each of said printheads comprises a line of inkjet nozzles, said printhead assembly can be moved relative to said light permeable material in orthogonal X-Y directions, and said printing comprises printing said plurality of ink layers in one pass of said printhead beam relative to said light permeable material. 
 
     
     
       4. A method as claimed in  claim 3 , wherein said X direction is parallel to the width of said sheet and said Y direction is parallel to the length of said sheet. 
     
     
       5. A method as claimed in  claim 3 , further comprising unrolling said sheet from a roll of transparent film material, wherein said sheet has said X and Y directions, said Y direction being a direction from which the sheet is unrolled from the roll, and wherein said print pattern comprises a pattern of lines in the X direction across the width of said sheet. 
     
     
       6. A method as claimed in  claim 3 , wherein said printing comprises printing said plurality of ink layers in one pass of said printhead assembly relative to said light permeable material. 
     
     
       7. A method as claimed in  claim 3 , wherein said plurality of printheads in said printhead assembly are in line. 
     
     
       8. A method as claimed in  claim 3 , wherein each said line of inkjet nozzles is supplied with a single color of UV curable ink, and the printhead assembly can be moved relative to said light permeable material such that the lines of nozzles are presented to said light permeable material and can print in the sequential order of said base layer, followed by said design layer. 
     
     
       9. A method as claimed in  claim 3 , wherein each said line of inkjet nozzles is supplied with a single color of UV curable ink, and the printhead assembly can be moved relative to said light permeable material such that the lines of nozzles are presented to said light permeable material and can print in the sequential order of said design layer, followed by said base layer. 
     
     
       10. A method as claimed in  claim 3 , wherein each said line of inkjet nozzles is supplied by a single color of UV curable ink. 
     
     
       11. A method as claimed in  claim 3 , wherein the printhead assembly can be moved relative to said light permeable material such that the lines of nozzles are presented and can print in one pass of the substrate in the sequential order of a black ink base layer, then a white ink base layer, followed by ink for said design color layer. 
     
     
       12. A method as claimed in  claim 3 , wherein said base layer and said design layer are printed in one direction of movement of said sheet relative to said printhead beam in one of said orthogonal X-Y directions. 
     
     
       13. A method as claimed in  claim 3 , wherein said base layer and said design layer are printed in one pass of the printhead assembly in one of said orthogonal X-Y directions. 
     
     
       14. A method as claimed in  claim 13 , wherein base layer colors of black and white and design layer colors of cyan, magenta, yellow and black are printed simultaneously in said one pass of the printhead assembly. 
     
     
       15. A method as claimed in claim  3  10, wherein said single color is one of white, cyan, magenta, yellow and black, wherein a leading channel of one line of nozzles is dedicated to printing said base layer, and wherein a trailing channel of another line of nozzles is dedicated to printing said design color layer. 
     
     
       16. A method as claimed in  claim 3 , wherein the configuration of said printheads is amended from one configuration of said printheads to another configuration of said printheads. 
     
     
       17. A method as claimed in  claim 3 , wherein said lines of inkjet nozzles are divided into a plurality of channels. 
     
     
       18. A method as claimed in  claim 17 , wherein firmware in said inkjet printer manages said plurality of channels to print a part of said base layer and a part of said design layer in the same pass of said printhead assembly relative to said light permeable material. 
     
     
       19. A method as claimed in  claim 18 , wherein said plurality of channels enable the printing of a plurality of base layers. 
     
     
       20. A method as claimed in  claim 19 , wherein said plurality of base layers comprises 2, 3 or 4 base layers. 
     
     
       21. A method as claimed in  claim 20 , wherein said plurality of base layers comprises black and white layers. 
     
     
       22. A method as claimed in  claim 18 , wherein said base layer is printed before said design layer. 
     
     
       23. A method as claimed in  claim 18 , wherein said design layer is printed before said base layer. 
     
     
       24. A method as claimed in  claim 18 , wherein a reverse-reading design layer is printed before said base layer, said base layer followed by a right-reading design layer. 
     
     
       25. A method as claimed in  claim 17 , wherein said plurality of channels comprises four channels. 
     
     
       26. A method as claimed in  claim 2 , wherein said printing further comprises printing said plurality of ink layers over the second part of the overall area of said print pattern. 
     
     
       27. A method as claimed in  claim 1 , wherein at a second point in time during said printing sequence after said one point in time, at least one of said plurality of ink layers are printed within the another of said printed portions. 
     
     
       28. A method as claimed in  claim 1 , wherein said sheet is a transparent material comprising two substantially parallel and plane surfaces. 
     
     
       29. A method as claimed in  claim 1 , wherein said base layer is white. 
     
     
       30. A method as claimed in  claim 29 , wherein said print pattern comprises another base layer, and wherein the color of said another base layer is one of black and white. 
     
     
       31. A method as claimed  claim 29 , wherein said another base layer is a composite black layer comprising cyan, magenta and yellow inks. 
     
     
       32. A method as claimed in  claim 1 , wherein said design layer comprises the colors of cyan, magenta, yellow and black in a four or six color process. 
     
     
       33. A method as claimed in  claim 1 , wherein said plurality of said plurality of printed portions comprise said design color layer. 
     
     
       34. A method as claimed in  claim 1 , wherein clear ink is printed within the print pattern. 
     
     
       35. A method as claimed in  claim 1 , wherein each of said plurality of printed portions is of width less than 10 mm. 
     
     
       36. A method as claimed in  claim 1 , wherein said printing of both said base layer and said design color layer is undertaken in one printing operation without removal of said light permeable material from said inkjet printer. 
     
     
       37. A method as claimed in  claim 1 , wherein said UV curable ink is applied unidirectionally. 
     
     
       38. A method as claimed in  claim 1 , wherein said UV curable ink is applied bidirectionally. 
     
     
       39. A method as claimed in  claim 1 , wherein said design layer is printed by means of computer software manipulation to create said design layer within said print pattern elements. 
     
     
       40. A method as claimed in  claim 1 , wherein computer software determines the positions of the printed portions and unprinted portions and causes the digital inkjet printer to eject ink from the digital inkjet printer solely within said printed portions during the printing of both said base layer and said design color layer. 
     
     
       41. A method as claimed in  claim 1 , wherein said printing of printed portions and the non-printing of said unprinted portions is determined by computer firmware in said inkjet printer. 
     
     
       42. A method as claimed in  claim 1 , wherein computer firmware in said inkjet printer determines the positions of the printed portions and unprinted portions and causes the digital inkjet printer to eject ink from the digital inkjet printer solely within said printed portions during the printing of both said base layer and said design color layer. 
     
     
       43. A method as claimed in  claim 1 , wherein said printing both said base layer and said design color layer by a digital inkjet printer comprises ejecting ink from said digital inkjet printer only within said printed portions. 
     
     
       44. A method as claimed in  claim 1 , wherein said digital inkjet printer is a flatbed printer. 
     
     
       45. A method as claimed in  claim 1 , wherein said design layer is visible from one side of the panel and is not visible from the other side of the panel. 
     
     
       46. A method as claimed in  claim 1 , wherein said print pattern comprises a white translucent base layer and a translucent design layer. 
     
     
       47. A method as claimed in  claim 1 , wherein there are at least one of three, four or five more of said plurality of ink layers printed within one of said printed portions than the number of said plurality of ink layers printed within another of said printed portions. 
     
     
       48. The method of claim 2, wherein a perceived design formed by the design layer is visually independent of a shape of said base layer.  
     
     
       49. A method as claimed in claim 2, wherein said base layer is white.  
     
     
       50. A method of making a panel comprising an imperforate sheet of colored or colorless light permeable material partially printed with a print pattern comprising a plurality of ink layers, said ink layers comprising a base layer, said ink layers comprising a design layer, said design layer comprising a design color layer, said print pattern comprising a plurality of connected and/or unconnected print pattern elements, said print pattern subdividing the panel into a plurality of areas of said print pattern and/or a plurality of unprinted areas of said light permeable material, and wherein the percentage of unprinted light permeable material is at least 5% and the light transmissivity of the panel is at least 10%, wherein a cross-section can be taken through said panel comprising two outer edges of said sheet of light permeable material and alternate printed portions and unprinted portions and a plurality of said printed portions comprising a part of said base layer and a plurality of said plurality of said printed portions comprising a part of said design layer, said method comprising:
 (i) providing a substantially imperforate sheet of colored or colorless light permeable material, and   (ii) printing both said base layer and said design layer by a digital inkjet printer, wherein all said plurality of ink layers are applied within said printed portions and are not applied within said unprinted portions, wherein said printing is undertaken in a printing sequence, and wherein at one point in time during said printing sequence there are at least two more of said plurality of ink layers printed within one of said printed portions than the number of said plurality of ink layers printed within another of said printed portions, wherein said printing comprises simultaneously printing a portion of said base layer and a portion of said design layer.